Heretofore, the moisture sensitive section of the element that has the capability described above has been made of an electrolyte such as lithium chloride or calcium chloride, a vapor-deposited film of a semiconductor such as selenium or germanium, as well as a metal oxide or metal oxide ceramic using aluminum oxide, titanium oxide or iron oxide.
Among these materials, the electrolyte has so much hygroscopicity in the high-humidity region that is becomes fluid and has low strength, with the result that the measurable moisture range is from 0 to about 60% rh. The vapor-deposited semiconductor film needs vacuum deposition and is not easy to fabricate, and in addition, the humidity reading is affected by temperature. The metal oxide is stable both physically and chemically and provides a strong element, but it generally needs a firing temperature of 1000.degree. C. or more which often reduces the area of the moisture sensitive surface. Therefore, the conventional moisture sensitive sections prepared from either of the above mentioned materials have their own defect and are not satisfactory.